The Huldra 5.56 mid-length upper is a standard mil-spec upper that will work on any mil-spec AR lower. The mid-length piston system will give you the benefits of a longer forearm by giving the user a longer, more ergonomic grip, a longer sight radius between the front and rear sight for quicker sight acquisition and less felt recoil. Huldra's Adams Arms patented piston system technology will run cleaner, cooler, and longer than any other AR. The piston system parts and the barrel have been treated with our salt nitride Meloniting process, making them harder than hard chrome.

Our melonited corrosive resistant CrMoV 4150 barrels provides excellent coating uniformity and no tolerance build up in the barrel to create deviation. Our melonited barrels have higher lubricity, last longer and are just plain tougher than chrome lining. The barrel chambers are speed polished, reducing resistance on the cartridge entering and exiting the chamber.